IDE: guard against SourceFile -> URI conversion failing

This can happen for example when dealing with NoSource

Author: smarter

compiler/src/dotty/tools/dotc/interactive/Interactive.scala

@@ -475,7 +475,7 @@ object Interactive {
             Include.definitions | Include.overriding | Include.overridden)
         else sym.topLevelClass match {
           case cls: ClassSymbol =>
-            val trees = Option(cls.sourceFile).map(InteractiveDriver.toUri) match {
+            val trees = Option(cls.sourceFile).flatMap(InteractiveDriver.toUriOption) match {
               case Some(uri) if driver.openedTrees.contains(uri) =>
                 driver.openedTrees(uri)
               case _ => // Symbol comes from the classpath

compiler/src/dotty/tools/dotc/interactive/InteractiveDriver.scala

@@ -265,7 +265,24 @@ class InteractiveDriver(val settings: List[String]) extends Driver {
 }
 
 object InteractiveDriver {
-  def toUri(file: AbstractFile): URI = Paths.get(file.path).toUri
-  def toUri(source: SourceFile): URI = toUri(source.file)
+  def toUriOption(file: AbstractFile): Option[URI] =
+    if (!file.exists)
+      None
+    else
+      try {
+        // We don't use file.file here since it'll be null
+        // for the VirtualFiles created by InteractiveDriver#toSource
+        // TODO: To avoid these round trip conversions, we could add an
+        // AbstractFile#toUri method and implement it by returning a constant
+        // passed as a parameter to a constructor of VirtualFile
+        Some(Paths.get(file.path).toUri)
+      } catch {
+        case e: InvalidPathException =>
+          None
+      }
+  def toUriOption(source: SourceFile): Option[URI] =
+    if (!source.exists)
+      None
+    else
+      toUriOption(source.file)
 }
-

language-server/src/dotty/tools/languageserver/DottyLanguageServer.scala

@@ -315,7 +315,8 @@ class DottyLanguageServer extends LanguageServer
         Include.references | Include.definitions | Include.linkedClass | Include.overriding
       val refs = Interactive.findTreesMatching(trees, includes, sym)
 
-      val changes = refs.groupBy(ref => toUri(ref.source).toString)
+      val changes = refs.groupBy(ref => toUriOption(ref.source))
+        .flatMap((uriOpt, ref) => uriOpt.map(uri => (uri.toString, ref)))
         .mapValues(refs =>
           refs.flatMap(ref =>
             range(ref.namePos, positionMapperFor(ref.source)).map(nameRange => new TextEdit(nameRange, newName))).asJava)
@@ -433,7 +434,10 @@ object DottyLanguageServer {
 
   /** Convert a SourcePosition to an lsp4.Location */
   def location(p: SourcePosition, positionMapper: Option[SourcePosition => SourcePosition] = None): Option[lsp4j.Location] =
-    range(p, positionMapper).map(r => new lsp4j.Location(toUri(p.source).toString, r))
+    for {
+      uri <- toUriOption(p.source)
+      r <- range(p, positionMapper)
+    } yield new lsp4j.Location(uri.toString, r)
 
   /**
    * Convert a MessageContainer to an lsp4j.Diagnostic. The positions are transformed vy